The AROS distribution Icaros Desktop has made its next step towards compatibility with legacy Amiga workbench applications, including an entire AROS enviroment compiled for the classic Amiga platform, which is almost binary compatible with the original Amiga OS 3.1 (and its extensions). When the user needs an old program, he or she only has to fire up the AROS M68K environment and run the application. The Amiga virtual machine can optionally be set to run at startup like a system service.

Well, it's an 800 MB download.... I guess they must have a lot of compression going on there!

I have to really wonder what's taking up all that space. This is supposed to be a near-clone of Amiga OS, right? I remember when Amiga OS came on six 880K floppy disks (not counting the Kickstart ROM!). I know AROS has got a lot of additional stuff: dev kit (it was available separately for Amiga OS), a TCP/IP stack, email, web browser... not to mention AMOS Pro, Hurrican and various other apps... and drivers... but still. How did it get this big?

Well, it's an 800 MB download.... I guess they must have a lot of compression going on there!

Yes. That's 7zip magic: about 1/3rd of the real size.

I have to really wonder what's taking up all that space.

Easy. Download the distribution, mount the ISO somewhere, and use one of those apps that evaluate directory sizes.

This is supposed to be a near-clone of Amiga OS, right? I remember when Amiga OS came on six 880K floppy disks (not counting the Kickstart ROM!). I know AROS has got a lot of additional stuff: dev kit (it was available separately for Amiga OS), a TCP/IP stack, email, web browser... not to mention AMOS Pro, Hurrican and various other apps... and drivers... but still. How did it get this big?

Did the original 6x880k disks include a spreadsheet, a word processor, a couple of text editors, a data base, three different music trackers, a music composer, a multi-track audio editor, twenty games, emulators for about every old computer and gaming systems, a dozen of programming languages, tons of development tools and libraries, two internet browsers, many chat and mail clients, three full PDF manuals, an audio/video media player, a CD/DVD burning application, DirectoryOpus, and dozens of artistry stuff like pointers and wallpapers? I don't remember...

No, AROS is NOT a near clone of OS 3.1. The Amiga OS 3.1 API has been ported to AROS in an effort to make porting old Amiga 68K hardware-friendly programs to AROS x86 easier. AROS goes way beyond OS 3.1 in its hardware 3D support and for the support of other modern pieces of hardware. Hardware friendly apps from OS 3.1 can pretty much be recompiled as-is or with minimal changes and then run on AROS.